Electrically heated catalytic combustor

Abstract

The present disclosure is directed to a system comprising a recuperated gas turbine engine with a catalytic combustor, and methods of operating the same, the catalytic combustor comprising: (a) an upstream section comprising an electrical heater and (b) a downstream catalyst section, wherein the upstream section and the downstream catalyst section are disposed adjacent to and in fluid communication with one another.

What is claimed: 
     
       1. A system comprising a recuperated gas turbine engine with a catalytic combustor, the catalytic combustor comprising:
 (a) an upstream section comprising an electrical heater and 
 (b) a downstream catalyst section, wherein the upstream section and the downstream catalyst section are disposed adjacent to and in fluid communication with one another; 
 wherein the upstream section and the downstream catalyst section are integrated in a single unit; 
 wherein the upstream section and the downstream catalyst section each contain pores or channels; and 
 wherein the ratio of the pore or channel surface area of the upstream section to those of the downstream catalyst section are in a range of from about 0.5% to 50%. 
 
     
     
       2. The system of  claim 1 , wherein the upstream section further comprises an upstream catalyst. 
     
     
       3. The system of  claim 1 , wherein the downstream catalyst section further comprises a downstream catalyst. 
     
     
       4. The system of  claim 1 , wherein the upstream section comprising the electrical heater is the only initiation source in the catalytic combustor and no other source or ignition system is required. 
     
     
       5. The system of  claim 1 , wherein one or both of the upstream or downstream catalysts independently comprise a catalyst comprising Ag, Au, Cu, Co, Cr, Fe, Ir, Mo, Mn, Ni, Pd, Pt, Rh, Sc, Ti, V, W, Y, Zn, Zr, or a combination thereof, in either metallic or oxide form. 
     
     
       6. The system of  claim 1 , comprising a fuel/air mixing and/or a vaporizing device positioned upstream of the catalytic combustor, positioned to provide or modulate a fuel/air mixture into the catalytic combustor. 
     
     
       7. The system of  claim 1 , further comprising:
 (a) a compressor arranged to receive air and to compress the air; 
 (b) a fuel system operable to supply fuel into the compressor, such that a mixture of compressed air and fuel can be/is discharged from the compressor; 
 (c) a turbine arranged to receive the combustion gases, when present, from the catalytic combustor and to expand the gases to produce mechanical power that in part, drives the compressor; 
 (d) a heat exchanger or “recuperator” arranged to receive exhaust gases from the turbine and the air or mixture discharged from the compressor and cause heat exchange there between such that the air or mixture can be/is pre-heated before entering the catalytic combustor. 
 
     
     
       8. A mobile terrestrial, industrial, commercial, marine, or airborne power generator comprising the system of  claim 1 . 
     
     
       9. A method of operating a system comprising a recuperated gas turbine engine with a catalytic combustor, the catalytic combustor comprising: (a) an upstream section comprising an electrical heater and (b) a downstream catalyst section, wherein the upstream section and the downstream catalyst section are disposed adjacent to and in fluid communication with one another; wherein the upstream section and the downstream catalyst section are integrated in a single unit; wherein the upstream section and the downstream catalyst section each contain pores or channels; and wherein the ratio of the pore or channel surface area of the upstream section to those of the downstream catalyst section are in a range of from about 0.5% to 50%, the method comprising:
 (a) providing energy to the electrical heater to heat the upstream section to a temperature at least equal to the catalytic reaction temperature of a mixture of a fuel and air mixture, 
 (b) introducing a mass flow of the mixture of air and fuel to the heated upstream section, so as to initiate catalytic combustion, and 
 (c) maintaining or increasing the mass flow of the mixture of air and fuel through the catalyst, so as to provide a combusting mixture of fuel and air into the second section, the combusting mixture having an associated heat. 
 
     
     
       10. The method of  claim 9 , further comprising a step of modulating the mass flow and mixture of air and fuel to accommodate load requirements of the recuperated gas turbine engine system. 
     
     
       11. The method of  claim 9 , further comprising a step of de-energizing the electrical heater, while maintaining stable catalytic combustion. 
     
     
       12. The method of  claim 9 , further comprising a step of maintaining stable combustion before the inlet mixture has reached the catalytic light-off temperature. 
     
     
       13. The method of  claim 9 , the method further comprising de-energizing the electrical heater. 
     
     
       14. The method of  claim 9 , further comprising a step of maintaining or increasing the mass flow of the mixture of air and fuel through the heated catalyst, such that the heat associated with the combusting mixture of fuel and air, on contacting the downstream catalyst section, is sufficient to raise the temperature of at least a portion of the downstream catalyst section to an ignition temperature of the mixture of a fuel and air in the downstream catalyst section. 
     
     
       15. The method of  claim 14 , further comprising a step of maintaining the increased mass flow for a time sufficient to provide that substantially all of the downstream catalyst section is heated to at least the catalytic combustion temperature of the mixture of a fuel and air, so that stable catalytic combustion is maintained and can be increased. 
     
     
       16. The method of  claim 15 , further comprising a step of maintaining or increasing the mass flow until the recuperator is heated to the extent that air or air-fuel mixture is provided to the combustor at above the combustor core light-off temperature. 
     
     
       17. A method of operating a recuperative gas turbine engine of in a system with a catalytic combustor, the catalytic combustor comprising: (a) an upstream section comprising an electrical heater and (b) a downstream catalyst section, wherein the upstream section and the downstream catalyst section are disposed adjacent to and in fluid communication with one another; wherein the upstream section and the downstream catalyst section are integrated in a single unit; wherein the upstream section and the downstream catalyst section each contain pores or channels; and wherein the ratio of the pore or channel surface area of the upstream section to those of the downstream catalyst section are in a range of from about 0.5% to 50%; wherein the system further comprising
 (a) a compressor arranged to receive air and to compress the air; 
 (b) a fuel system operable to supply fuel into the compressor, such that a mixture of compressed air and fuel can be/is discharged from the compressor; 
 (c) a turbine arranged to receive the combustion gases, when present, from the catalytic combustor and to expand the gases to produce mechanical power that in part, drives the compressor; 
 (d) a heat exchanger or “recuperator” arranged to receive exhaust gases from the turbine and the air or mixture discharged from the compressor and cause heat exchange there between such that the air or mixture can be/is pre-heated before entering the catalytic combustor, 
 the method comprising: 
 (a) compressing at least air in the compressor; 
 (b) providing energy to the electrical heater to heat the upstream section to a temperature at least equal to an ignition temperature of a mixture of a fuel and the air; 
 (c) introducing a mass flow of the mixture of the fuel and air to the heated upstream section, such that the mixture of fuel and air is combusted in the upstream section; 
 (d) increasing the mass flow of the mixture of the fuel and air such that the flow of combusting mixture heats the downstream catalytic section to above an ignition temperature of the downstream catalyst section; 
 (e) maintaining the mass flow of the mixture of fuel and air through the upstream section and the downstream catalyst section so that the mixture of fuel and air, as it passes through the downstream catalyst section, is combusted therein to form heated combustion gases that exit the downstream catalyst section; 
 (f) directing at least a portion of the heated combustion gases exiting the downstream catalyst section and the catalytic combustor through the turbine to produce mechanical power, and using the mechanical power in part to drive the compressor; 
 (g) directing some or all of the heated combustion gases passing through the turbine to the recuperator; and 
 (h) using the heated combustion gases in the recuperator to preheat the mixture of the fuel and air being introduced to the heated upstream section. 
 
     
     
       18. The method of  claim 17 , further comprising modulating the mass flow of the mixture of the fuel and air introduced to the upstream section. 
     
     
       19. The method of  claim 17 , wherein the mixture of fuel and air has a k-value of greater than 1, the method further comprises modulating the k-value of the mixture of fuel and air during the course of combustion.